MGate MB3000 Modbus Gateway User’s Manual Second Edition, August 2007 www.moxa.com/product Moxa Technologies Co., Ltd. Tel: Fax: Web: +886-2-8919-1230 +886-2-8919-1231 www.moxa.com MOXA Technical Support support@moxa.com Worldwide: support@usa.moxa.
MGate MB3000 Modbus Gateway User’s Manual The software described in this manual is furnished under a license agreement and may be used only in accordance with the terms of that agreement. Copyright Notice Copyright © 2007 Moxa Technologies Co., Ltd. All rights reserved. Reproduction without permission is prohibited. Trademarks MOXA is a registered trademark of The Moxa Group. All other trademarks or registered marks in this manual belong to their respective manufacturers.
Table of Contents Chapter 1 Introduction ...............................................................................................1-1 Overview .............................................................................................................................. 1-2 Package Checklist................................................................................................................. 1-3 Product Features ...............................................................................
LED Indicators ..................................................................................................................... 5-2 Dimensions........................................................................................................................... 5-3 Jumpers................................................................................................................................. 5-4 Pin Assignments ................................................................................
Ethernet Masters with Multiple Serial Slaves....................................................................... 8-2 Serial Masters with Multiple Ethernet Slaves....................................................................... 8-2 Modbus TCP Masters with ASCII and RTU Slaves ............................................................. 8-3 Serial Master with Serial Slaves over Internet......................................................................
1 Chapter 1 Introduction Welcome to the MGate MB3000 line of Modbus gateways. All models feature easy integration of Modbus TCP to Modbus RTU/ASCII and feature RS-232/422/485 ports for Modbus serial communication. One, two, and four-port models are available.
MGate MB3000 User’s Manual Hardware Reference: MB3270, MB3270I Overview The MGate MB3000 is a line of protocol gateways that provides users with z seamless integration of Ethernet and serial Modbus devices z powerful operation modes to handle almost any Modbus application z Windows utilities for easy setup and traffic monitoring Seamless integration of Ethernet and serial Modbus devices Modbus is one of the most popular automation protocols in the world, supporting traditional RS-232/422/485 devices
MGate MB3000 User’s Manual Hardware Reference: MB3270, MB3270I Package Checklist All models in the MGate MB3000 line are shipped with the following items: Standard Accessories z 1 MGate MB3000 Modbus gateway z Document & software CD z Quick Installation Guide z Power adaptor (MB3180 only) z Product warranty statement Optional Accessories z DK-35A: DIN-rail mounting kit (35 mm) z DR-4524: 45W/2A DIN-rail 24 VDC power supply with universal 85 to 264 VAC input z DR-75-24: 75W/3.
2 Chapter 2 Getting Started This chapter provides basic instructions for installing the MGate MB3000.
MGate MB3000 User’s Manual Getting Started Connecting Power The unit can be powered using the AC adaptor or by connecting a power source to the terminal block, depending on the model. The following instructions are for the AC adaptor: 1. Plug the connector of the power adapter into the DC-IN jack on the back of the unit. 2. Plug the power adapter into an electrical outlet. 3. Follow these instructions to connect a power source to the terminal block: 4.
MGate MB3000 User’s Manual Getting Started ATTENTION Do not use the 1 KΩ pull high/low setting on the MGate MB3000 when using the RS-232 interface. Doing so will degrade the RS-232 signals and reduce the effective communication distance. Connecting to a Host or the Network A 10/100BaseT Ethernet port is located on the unit’s front panel.
3 Chapter 3 Hardware: MB3180 This chapter provides hardware information for the MGate MB3180.
MGate MB3000 User’s Manual Hardware: MB3180 Panel Layout Rear Panel View RJ45 10/100M Ethernet port Reset button Power input Top Panel View DIN-rail kit screw hole Wallmount screw hole Front Panel View Male DB9 serial port Stick-on pad LED Indicators Name Color Red Ready Green Ethernet P1 Tx/Rx Off Orange Green Off Orange Green Off Function Steady on: Power is on and unit is booting up. Blinking: Indicates an IP conflict, or DHCP or BOOTP server is not responding properly.
MGate MB3000 User’s Manual Hardware: MB3180 Dimensions 3-3
MGate MB3000 User’s Manual Hardware: MB3180 Jumpers JP 3 JP 4 To set the pull high/low resistors to 150 KΩ, leave jumpers JP3 and JP4 open (not shorted). This is the default setting. To set the pull high/low resistors to 1 KΩ, short jumpers JP3 and JP4 with jumper caps. ATTENTION Do not use the 1 KΩ pull high/low setting on the MGate MB3000 when using the RS-232 interface. Doing so will degrade the RS-232 signals and reduce the effective communication distance.
MGate MB3000 User’s Manual Hardware: MB3180 Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3180 Specifications LAN Ethernet Protection 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Serial Interface Interface RS-232/422/485 No.
4 Chapter 4 Hardware: MB3280 This chapter provides hardware information for the MGate MB3280.
MGate MB3000 User’s Manual Hardware: MB3280 Panel Layout Rear Panel View Reset button RJ45 10/100M Ethernet port Power input Top Panel View DIN-Rail screw hole Wallmount screw hole Front Panel View Male DB9 serial port Stick-on pad LED Indicators Name Color Red Ready Green Ethernet P1 and P2 Off Orange Green Off Orange Green Off Function Steady on: Power is on and unit is booting up. Blinking: Indicates an IP conflict, or DHCP or BOOTP server is not responding properly.
MGate MB3000 User’s Manual Hardware: MB3280 34mm (1.33 in) 111 mm(4.37 in) 3.5 mm (0.14 in) 43 mm(1.69 in) 7mm (0.28 in) 5 mm (0.20 in) 1 0 mm(0.39 in) 4 mm(0.16 in) 25 mm(0.98 in) 55.5 mm(2.19 in) 50.5 mm(1.99 in) 43 mm(1.69 in) 9 mm(0.35 in) Dimensions 34 mm (1.34 in) 77 mm (3.03 in) 88 mm (3.46 in) 100 mm (3.94 in) 4-3 21.5 mm (0.
MGate MB3000 User’s Manual Hardware: MB3280 Jumpers 12 3 4 1 23 4 To add a 120 Ω termination resistor, set switch 3 on the port’s assigned DIP switch to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to OFF. This is the default setting. To set the pull high/low resistors to 1 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to ON.
MGate MB3000 User’s Manual Hardware: MB3280 Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3280 Specifications LAN Ethernet Protection 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Serial Interface Interface RS-232/422/485 No.
5 Chapter 5 Hardware: MB3480 This chapter provides hardware information for the MGate MB3480.
MGate MB3000 User’s Manual Hardware: MB3480 Panel Layout Power input LAN RESET V+ V- RJ45 10/100 Mbps Ethernet port Terminal Block power input Indicator LEDs Male DB9 serial port LED Indicators Name Color Red Ready Green Ethernet P1, P2 P3, P4 Off Orange Green Off Orange Green Off Function Steady on: Power is on and unit is booting up. Blinking: Indicates an IP conflict, or DHCP or BOOTP server is not responding properly. Steady on: Power is on and unit is functioning normally.
MGate MB3000 User’s Manual Hardware: MB3480 Dimensions LAN RESET V+ V- 35.5 mm (1.4 in ) 39 mm 25 mm (1.54 in) (0.98 in) 103 mm (4.06 in) O 3.2 mm (0.13 in) 158 mm (6.22 in) 169 mm (6.67 in) 181 mm (7.
MGate MB3000 User’s Manual Hardware: MB3480 Jumpers To add a 120 Ω termination resistor, set switch 3 on the port’s assigned DIP switch to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to OFF. This is the default setting. To set the pull high/low resistors to 1 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to ON.
MGate MB3000 User’s Manual Hardware: MB3480 Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3480 DIN-Rail, Wall Mounting Mounting on a DIN-rail: You will first need to attach the mounting plates (included) to the unit. Attach the DIN-rail accessories to the mounting plates and latch the unit onto the DIN-rail as shown. The DIN-rail kit is ordered separately. ⇒ Mounting on the wall: You will first need to attach the mounting plates to the unit. Place four screws in the wall and slide the unit onto the screws as shown. 4 mm 2.5 cm 16.
MGate MB3000 User’s Manual Hardware: MB3480 Specifications LAN Ethernet Protection 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Serial Interface Interface RS-232/422/485 No.
6 Chapter 6 Hardware: MB3170, MB3170I This chapter provides hardware information for the MGate MB3170 and MB3170I.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Panel Layout Dual Power Input and Relay Output Reset LED Indicators Reset RS-232 RS-422/485 Copper Ethernet MB3170 LED Indicators Name PWR1 PWR2 Color Red Red Red RDY Green Ethernet P1 Off Orange Green Off Orange Green Off Function Power is being supplied to the power input. Power is being supplied to the power input. Steady on: Power is on and unit is booting up.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Dimensions 29 mm (1.14 in) 14.5 mm (0.57 in) 124.5 mm (4.9 in) 89.2 mm (3.51 in) 118.5 mm (4.67 in) 20 mm (0.79 in) 69.5 mm (2.74 in) 14.5 mm (0.57 in) 20.6 mm 29.91 mm (0.81 in) (1.18 in) 11.5 mm (0.45 in) 25.9 mm (1.02 in) 35 mm (1.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Jumpers SW 1 The DIP switches are located beneath the DIP switch panel on the side of the unit. To add a 120 Ω termination resistor, set switch 3 to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 to OFF. This is the default setting. To set the pull high/low resistors to 1 KΩ, set switches 1 and 2 to ON.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Pin Assignments DB9 (Male) The MGate MB3170 and MB3170I use a DB9 (male) serial port for RS-232 connections to Modbus RTU or ASCII devices. 1 6 5 9 Pin RS-232 1 2 3 4 5 6 7 8 DCD RxD TxD DTR GND DSR RTS CTS Terminal Block (RS-422, RS-485) The MGate MB3170 and MB3170I use a terminal block connector for RS-422 and RS-485 connections to Modbus RTU or ASCII devices.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I DIN-Rail, Wall Mounting There are two sliders on the back of the unit for DIN-rail and wall mounting. Mounting on a DIN-rail: Pull out the bottom slider, latch the unit onto the DIN-rail, and push the slider back in. Mounting on the wall: Pull out both the top and bottom sliders and align the screws accordingly.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Specifications LAN Ethernet Protection 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Serial Interface Interface RS-232/422/485 No.
7 Chapter 7 Hardware: MB3270, MB3270I This chapter provides hardware information for the MGate MB3270 and MB3270I.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Panel Layout Dual Power Input and Relay Output Reset LED Indicators Reset RS-232/422/485 Copper Ethernet MB3270 LED Indicators Name PWR1 PWR2 Color Red Red Red RDY Green Ethernet P1, P2 Off Orange Green Off Orange Green Off Function Power is being supplied to the power input. Power is being supplied to the power input. Steady on: Power is on and unit is booting up.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Dimensions 29 mm (1.14 in) 14.5 mm (0.57 in) 124.5 mm (4.9 in) 89.2 mm (3.51 in) 118.5 mm (4.67 in) 20 mm (0.79 in) 69.5 mm (2.74 in) 14.5 mm (0.57 in) 20.6 mm 29.91 mm (0.81 in) (1.18 in) 11.5 mm (0.45 in) 25.9 mm (1.02 in) 35 mm (1.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Jumpers SW 2 SW 1 The DIP switches are located beneath the DIP switch panel on the side of the unit. To add a 120 Ω termination resistor, set switch 3 on the port’s assigned DIP switch to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to OFF. This is the default setting.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I DIN-Rail, Wall Mounting There are two sliders on the back of the unit for DIN-rail and wall mounting. Mounting on a DIN-rail: Pull out the bottom slider, latch the unit onto the DIN-rail, and push the slider back in. Mounting on the wall: Pull out both the top and bottom sliders and align the screws accordingly.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Specifications LAN Ethernet Protection 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Serial Interface Interface RS-232/422/485 No.
8 Chapter 8 Typical Applications In this chapter, we introduce four typical Modbus applications.
MGate MB3000 User’s Manual Typical Applications Ethernet Masters with Multiple Serial Slaves Connect all Modbus devices over an Ethernet network Most modern PLCs and host computers support Modbus TCP over Ethernet. In order to access discrete Modbus RTU/ASCII devices for data collection and control, they can rely on the MGate MB3000 Modbus gateway. The MGate MB3000 supports Modbus TCP with up to 16 simultaneous connections.
MGate MB3000 User’s Manual Typical Applications Modbus TCP Masters with ASCII and RTU Slaves Link TCP master devices with both ASCII and RTU serial devices simultaneously When integrating Modbus networks, you may encounter different Modbus serial networks that use different baudrates or a different protocol. Modbus ASCII might be used by some devices, while Modbus RTU is used by other devices.
9 Configuring the Modbus Gateway Chapter 9 We discuss the following topics in this chapter: Installing the Software Starting MGate Manager ¾ Connecting to the Unit ¾ ¾ Specify by IP Address Configure Serial Port for RTU or ASCII, Master or Slave Configure IP Address and Other Network Settings Configure Serial Communication Parameters Set up Slave ID Mapping (Smart Routing) Customize Modbus Settings Set Up Priority Control Verifying Location of Unit Monitoring Modbus Activity ¾ ¾ ¾ B
MGate MB3000 User’s Manual Configuring the Modbus Gateway Installing the Software The following instructions explain how to install MGate Manager, a utility for configuring and monitoring MGate MB3000 units over the network. 1. Insert the Document and Software CD into the CD-ROM drive. Locate and run the following setup program to begin the installation process: MGM_Setup_[Version]_Build_[DateTime].exe The latest version might be named MGM_Setup_Ver1.1.0_Build_xxxxxxxx.exe, for example: 2.
MGate MB3000 User’s Manual Configuring the Modbus Gateway 4. When the Select Additional Tasks window appears, click Next to continue. You may select Create a desktop icon if you would like a shortcut to MGate Manager on your desktop. 5. Click Next to start copying the software files. 6. A progress bar will appear. The procedure should take only a few seconds to complete.
MGate MB3000 User’s Manual Configuring the Modbus Gateway 7. A message will indicate that MGate Manager is successfully installed. You may choose to run it immediately by selecting Launch MGate Manager. 8. You may also open MGate Manager through Start Æ Programs Æ MGate Manager Æ MGate Manager, as shown below.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Starting MGate Manager MGate Manager is a Windows-based utility that is used to configure the MGate MB3000. Before running MGate Manager, make sure that your PC and the MGate MB3000 are connected to the same network. Alternatively, the MGate MB3000 may be connected directly to the PC for configuration purposes. Please refer to Chapter 2 for more details.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Change Language Setting If you wish to run MGate Manager in a different language, you may click Language to change the language setting. A dialog box showing the available languages should appear as shown below. When you click OK, MGate Manager will immediately reflect your chosen language. ATTENTION Use “Default Language” before contacting MOXA Technical Support.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Connecting to the Unit MGate Manager needs to connect to the unit before the unit can be configured. There are two methods to connect to the unit. Broadcast Search is used to find every MGate MB3000 on the LAN. Search by IP attempts to connect to a specific unit by IP address, which is useful if the unit is located outside the LAN or can only be accessed by going through a router.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Specify by IP Address Click Specify by IP Address if you know the IP address of the unit and wish to connect to it directly. A dialog box will appear. Enter the unit’s IP address and click OK. If the search is successful, the unit will be listed in MGate Manager. Click the unit to begin configuration. ATTENTION If Search by IP Address fails to locate the MGate MB3000, the IP address that you entered might be incorrect.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Modifying the Configuration Once your unit is displayed in MGate Manager, select it by clicking on it. The Configuration button will become available. Click Configuration to open the configuration window.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Configure Serial Port for RTU or ASCII, Master or Slave The Mode tab is where each serial port’s operation mode is configured. The operation mode determines whether the device(s) that are connected to the serial port will operate as a master or a slave, and whether the Modbus RTU or Modbus ASCII protocol will be used.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Configure IP Address and Other Network Settings The Network tab is where the unit’s network settings are configured. You can modify the Name, Network Configuration, IP Address, Netmask, Default Gateway, and DNS. You may also select a Password to protect the unit from unauthorized access. Parameter Value Name (an alphanumeric string) Network Configuration Static IP, DHCP, BootP, or DHCP/BootP IP Address 192.168.127.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Parameter Value Password (an alphanumeric string) Confirm password (an alphanumeric string) Notes You can set a password to prevent unauthorized users from configuring the unit. The password will be required when anyone attempts to configure the unit over the network. Modbus operation is not affected by the password. Re-type the password again for confirmation.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Configure Serial Communication Parameters The Serial tab is where each serial port’s communication parameters are configured. You can configure Baud Rate, Parity, Stop Bit, Flow Control, FIFO, and Interface Mode.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Set up Slave ID Mapping (Smart Routing) The Slave ID Map tab is where slave IDs are managed. The definitions on this tab determine how requests will be routed by the unit. How Slave IDs are Mapped on the MGate MB3000 When a Modbus master requests information from a Modbus slave, the request is addressed to the desired slave's ID, which must be unique on the network.
MGate MB3000 User’s Manual Configuring the Modbus Gateway With the slave ID map, smart routing is achieved for units with multiple serial ports. Since each virtual slave ID is routed to a specific Modbus network, requests are not broadcast over all serial ports. This keeps communication efficient and prevents devices on one port from slowing down the whole system.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Customize Modbus Settings The Modbus tab is where certain adjustments can be made to fine tune the communication between different Modbus networks. You can configure Initial Delay, Modbus TCP Exception, Slave Channel, and Response Time-out.
MGate MB3000 User’s Manual Configuring the Modbus Gateway ATTENTION Please note the following regarding automatic calibration of response timeouts: When automatically detecting the response timeout, the MGate will use the slave ID map to determine which ports and which IDs to search. Make sure that you have defined the slave ID map for your system before clicking “Auto Detection”. The automatic calibration will take some time to complete.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Set Up Priority Control The Priority Control tab is where emergency requests are enabled and configured. This is available for advanced models only (MB3170, MB3170I, MB3270, and MB3470). Priority control is designed for requests that are sent to Modbus RTU/ASCII slaves. Since Modbus RTU/ASCII slaves cannot handle multiple requests, the Modbus gateway must send each request individually and wait for the response before sending the next request.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Verifying Location of Unit If you are managing multiple MGate units, you may wonder if you are configuring the correct unit in MGate Manager. You can select a unit in MGate Manager and click Locate to make that unit’s “Ready” LED blink for a few seconds. This will tell you which physical unit corresponds with the unit that you selected.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Monitoring Modbus Activity For troubleshooting or management purposes, you can monitor the data passing through any MGate MB3000 on the network. Data events will be logged as they pass through the gateway. Rather than simply echoing the data, MGate Manager presents the data in an intelligent, easily-understood format, with clearly designated fields including source, type, destination, contents, and more.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Open Traffic Monitor Window Select the unit that you wish to monitor and click Monitor to open the Traffic Monitor window. In the Traffic Monitor window, click Start to begin live monitoring of the data passing through the selected MGate MB3000 unit.
MGate MB3000 User’s Manual Configuring the Modbus Gateway To stop capturing the log, press the Stop button.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Filter Traffic Information By default, all events are displayed in the traffic monitor window. MGate Manager also allows the data to be filtered so only the relevant information is displayed. The filter is selected using the radio buttons and customized using the “Filter info” field, as follows: Filter All Exception only Customization VSID=< virtual slave ID> (e.g., “VSID=1”) SID only RSID=< actual slave ID> (e.g.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Save Log to File To save the data log to a file, click Save. You may retrieve a saved log by clicking Load.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Upgrading Firmware Firmware updates for the MGate MB3000 are located at www.moxa.com. After you have downloaded the new firmware onto your PC, you can use MGate Manager to write it onto your MGate MB3000. Select the desired unit from the list in MGate Manager and click Upgrade Firmware to begin the process. The dialog boxes will guide you through the process. You will need to browse your PC for the firmware file.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Once the firmware has been successfully written onto the unit, click Exit to close the Upgrade Firmware window. MGate Manager will automatically execute a Broadcast Search for all MGate MB3000 units on the LAN. Your MGate should reappear in the list of units.
10 Chapter 10 We discuss the following topics in this chapter: DB9 (Male) Terminal Block (RS-422, RS-485) Power Input, Relay Output Pin Assignments
MGate MB3000 User’s Manual Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Pin Assignments Terminal Block (RS-422, RS-485) The MB3170 and MB3170I have a terminal block connector for RS-422 and RS-485 signals.
11 Chapter 11 Case Studies We discuss the following topics in this chapter: Introduction Replace Serial Masters with Ethernet Master(s), Slave IDs are Configurable Replace Serial Masters with Ethernet Master(s), Slave IDs are Fixed Keep Serial Master and Add Ethernet Master(s) Integrate Modbus RTU, ASCII, and TCP at the Same Time
MGate MB3000 User’s Manual Case Studies Introduction There are many reasons a Modbus gateway might be used to integrate Modbus networks. However, every situation has its own requirements and difficulties. Users may wonder how the gateway can help or even if the gateway is suitable for the system. This chapter presents some case studies to help guide. If you can not find the case the same as yours, it does not mean the MGate MB3000 is not suitable with you.
MGate MB3000 User’s Manual Case Studies Replace Serial Masters with Ethernet Master(s), Slave IDs are Fixed Some legacy Modbus slave devices have fixed IDs that cannot be changed. In order to integrate the devices into a Modbus TCP network, a multiport MGate model (MB3280, MB3270, or MB3480) can be used to assign virtual slave IDs. For more information about virtual slave IDs, please refer to Chapter 9.
MGate MB3000 User’s Manual Case Studies Keep Serial Master and Add Ethernet Master(s) In this scenario, the serial control system is a direct, low-latency system. The serial master must not be replaced, but Ethernet masters will need to have access to the serial slaves for monitoring or supervision. An advanced multiport MGate model (MB3270 or MB3470) can be inserted into the serial system, with the slaves connected to one serial port and the master to another serial port.
MGate MB3000 User’s Manual Case Studies Integrate Modbus RTU, ASCII, and TCP at the Same Time There can be a wide range in number, type, and sophistication of devices on the factory floor. The most common devices are simple serial-based meters, which report certain information relating to factory environment or equipment. However, other Modbus serial slaves may be as complex as a manufacturing machine or a PLC controller.
A Appendix A Modbus Overview Introduction Modbus is one of the most popular automation protocols in the world. It supports both serial and Ethernet devices. Many industrial devices, such as PLCs, DCSs, HMIs, instruments, meters, motors, and drivers, use Modbus as their communication standard. Devices are Either Masters or Slaves All Modbus devices are classified as either a master or a slave. Masters initiate all communication with slaves and do not communicate to other masters.
MGate MB3000 User’s Manual Modbus Overview Communication is by Request and Response All Modbus communication is by request and response. A master sends a request and a slave sends a response. The master will wait for the slave’s response before sending the next request. For broadcast commands, no response is expected. This is illustrated by three scenarios as follows: Normal The master sends a request to the slave. The slave sends a response with the requested information.
MGate MB3000 User’s Manual Modbus Overview Requests Need a Time Limit The original Modbus protocol was not designed for simultaneous requests or simultaneous masters, so only one request on the network can be handled at a time. When a master sends a request to a slave, no other communication may be initiated until after the slave responds. The Modbus protocol specifies that masters use a response timeout function to identify when a slave is nonresponsive due to device or line failure.
MGate MB3000 User’s Manual Modbus Overview Integrate Modbus Serial and Ethernet with Gateways Ordinarily, Modbus TCP and Modbus ASCII/RTU are unable to communicate with each other. However, with a Modbus gateway in between the Modbus serial network and the Modbus Ethernet network, TCP masters are able to communicate with serial slaves and serial masters are able to communicate with TCP slaves.
B Appendix B Declaration of Conformity Manufacturer’s Name: Moxa Technologies Co., Ltd. Fl.4, No.135, Lane 235, Pao-Chiao Rd., Shing Tien City, Manufacturer’s Taipei, Taiwan, R.O.C.
